Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
From:   Huacai Chen <chenhuacai@loongson.cn>
To:     Arnd Bergmann <arnd@arndb.de>, Andy Lutomirski <luto@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        David Airlie <airlied@linux.ie>,
        Jonathan Corbet <corbet@lwn.net>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     linux-arch@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, Xuefeng Li <lixuefeng@loongson.cn>,
        Yanteng Si <siyanteng@loongson.cn>,
        Huacai Chen <chenhuacai@gmail.com>,
        Guo Ren <guoren@kernel.org>, Xuerui Wang <kernel@xen0n.name>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Huacai Chen <chenhuacai@loongson.cn>
Subject: [PATCH V9 21/24] LoongArch: Add zboot (compressed kernel) support
Date:   Sat, 30 Apr 2022 17:05:15 +0800
Message-Id: <20220430090518.3127980-22-chenhuacai@loongson.cn>
In-Reply-To: <20220430090518.3127980-1-chenhuacai@loongson.cn>
References: <20220430090518.3127980-1-chenhuacai@loongson.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

This patch adds zboot (self-extracting compressed kernel) support, all
existing in-kernel compressing algorithm and efistub are supported.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
 arch/loongarch/Kbuild                         |   2 +-
 arch/loongarch/Kconfig                        |  11 ++
 arch/loongarch/Makefile                       |  26 ++-
 arch/loongarch/boot/Makefile                  |  55 ++++++
 arch/loongarch/boot/boot.lds.S                |  64 +++++++
 arch/loongarch/boot/decompress.c              |  98 +++++++++++
 arch/loongarch/boot/string.c                  | 166 ++++++++++++++++++
 arch/loongarch/boot/zheader.S                 | 100 +++++++++++
 arch/loongarch/boot/zkernel.S                 |  99 +++++++++++
 arch/loongarch/tools/Makefile                 |  15 ++
 arch/loongarch/tools/calc_vmlinuz_load_addr.c |  51 ++++++
 arch/loongarch/tools/elf-entry.c              |  66 +++++++
 12 files changed, 749 insertions(+), 4 deletions(-)
 create mode 100644 arch/loongarch/boot/boot.lds.S
 create mode 100644 arch/loongarch/boot/decompress.c
 create mode 100644 arch/loongarch/boot/string.c
 create mode 100644 arch/loongarch/boot/zheader.S
 create mode 100644 arch/loongarch/boot/zkernel.S
 create mode 100644 arch/loongarch/tools/Makefile
 create mode 100644 arch/loongarch/tools/calc_vmlinuz_load_addr.c
 create mode 100644 arch/loongarch/tools/elf-entry.c

diff --git a/arch/loongarch/Kbuild b/arch/loongarch/Kbuild
index ab5373d0a24f..d907fdd7ca08 100644
--- a/arch/loongarch/Kbuild
+++ b/arch/loongarch/Kbuild
@@ -3,4 +3,4 @@ obj-y += mm/
 obj-y += vdso/
 
 # for cleaning
-subdir- += boot
+subdir- += boot tools
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 55225ee5f868..6c1042746b2d 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -107,6 +107,7 @@ config LOONGARCH
 	select PERF_USE_VMALLOC
 	select RTC_LIB
 	select SPARSE_IRQ
+	select SYS_SUPPORTS_ZBOOT
 	select SYSCTL_EXCEPTION_TRACE
 	select SWIOTLB
 	select TRACE_IRQFLAGS_SUPPORT
@@ -143,6 +144,16 @@ config LOCKDEP_SUPPORT
 	bool
 	default y
 
+config SYS_SUPPORTS_ZBOOT
+	bool
+	select HAVE_KERNEL_GZIP
+	select HAVE_KERNEL_BZIP2
+	select HAVE_KERNEL_LZ4
+	select HAVE_KERNEL_LZMA
+	select HAVE_KERNEL_LZO
+	select HAVE_KERNEL_XZ
+	select HAVE_KERNEL_ZSTD
+
 config MACH_LOONGSON32
 	def_bool 32BIT
 
diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile
index d88a792dafbe..1ed5b8466565 100644
--- a/arch/loongarch/Makefile
+++ b/arch/loongarch/Makefile
@@ -5,12 +5,31 @@
 
 boot	:= arch/loongarch/boot
 
+ifndef CONFIG_SYS_SUPPORTS_ZBOOT
+
 ifndef CONFIG_EFI_STUB
 KBUILD_IMAGE	= $(boot)/vmlinux
 else
 KBUILD_IMAGE	= $(boot)/vmlinux.efi
 endif
 
+else
+
+ifndef CONFIG_EFI_STUB
+KBUILD_IMAGE	= $(boot)/vmlinuz
+else
+KBUILD_IMAGE	= $(boot)/vmlinuz.efi
+endif
+
+endif
+
+load-y		= 0x9000000000200000
+bootvars-y	= VMLINUX_LOAD_ADDRESS=$(load-y)
+
+archscripts: scripts_basic
+	$(Q)$(MAKE) $(build)=arch/loongarch/tools elf-entry
+	$(Q)$(MAKE) $(build)=arch/loongarch/tools calc_vmlinuz_load_addr
+
 #
 # Select the object file format to substitute into the linker script.
 #
@@ -55,9 +74,6 @@ KBUILD_CFLAGS_MODULE		+= -fplt -Wa,-mla-global-with-abs,-mla-local-with-abs
 cflags-y += -ffreestanding
 cflags-y += $(call as-option,-Wa$(comma)-mno-fix-loongson3-llsc,)
 
-load-y		= 0x9000000000200000
-bootvars-y	= VMLINUX_LOAD_ADDRESS=$(load-y)
-
 drivers-$(CONFIG_PCI)		+= arch/loongarch/pci/
 
 KBUILD_AFLAGS	+= $(cflags-y)
@@ -99,7 +115,11 @@ $(KBUILD_IMAGE): vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $(bootvars-y) $@
 
 install:
+ifndef CONFIG_SYS_SUPPORTS_ZBOOT
 	$(Q)install -D -m 755 $(KBUILD_IMAGE) $(INSTALL_PATH)/vmlinux-$(KERNELRELEASE)
+else
+	$(Q)install -D -m 755 $(KBUILD_IMAGE) $(INSTALL_PATH)/vmlinuz-$(KERNELRELEASE)
+endif
 	$(Q)install -D -m 644 .config $(INSTALL_PATH)/config-$(KERNELRELEASE)
 	$(Q)install -D -m 644 System.map $(INSTALL_PATH)/System.map-$(KERNELRELEASE)
 
diff --git a/arch/loongarch/boot/Makefile b/arch/loongarch/boot/Makefile
index 66f2293c34b2..c26a36004ae2 100644
--- a/arch/loongarch/boot/Makefile
+++ b/arch/loongarch/boot/Makefile
@@ -21,3 +21,58 @@ quiet_cmd_eficopy = OBJCOPY $@
 
 $(obj)/vmlinux.efi: $(obj)/vmlinux FORCE
 	$(call if_changed,eficopy)
+
+# zboot
+extra-y	+= boot.lds
+$(obj)/boot.lds: $(obj)/vmlinux.bin FORCE
+CPPFLAGS_boot.lds = $(KBUILD_CPPFLAGS) -DVMLINUZ_LOAD_ADDRESS=$(zload-y)
+
+entry-y	= $(shell $(objtree)/arch/loongarch/tools/elf-entry $(obj)/vmlinux)
+zload-y = $(shell $(objtree)/arch/loongarch/tools/calc_vmlinuz_load_addr \
+				$(obj)/vmlinux.bin $(VMLINUX_LOAD_ADDRESS))
+
+BOOT_HEAP_SIZE	:= 0x400000
+BOOT_STACK_SIZE	:= 0x002000
+
+KBUILD_AFLAGS := $(KBUILD_AFLAGS) -D__ASSEMBLY__ \
+	-DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) \
+	-DBOOT_STACK_SIZE=$(BOOT_STACK_SIZE)
+
+KBUILD_CFLAGS := $(KBUILD_CFLAGS) -fpic -D__KERNEL__ \
+	-DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) \
+	-DBOOT_STACK_SIZE=$(BOOT_STACK_SIZE)
+
+targets += vmlinux.bin
+OBJCOPYFLAGS_vmlinux.bin := $(OBJCOPYFLAGS) -O binary $(strip-flags)
+$(obj)/vmlinux.bin: $(obj)/vmlinux FORCE
+	$(call if_changed,objcopy)
+
+tool_$(CONFIG_KERNEL_GZIP)    = gzip
+tool_$(CONFIG_KERNEL_BZIP2)   = bzip2_with_size
+tool_$(CONFIG_KERNEL_LZ4)     = lz4_with_size
+tool_$(CONFIG_KERNEL_LZMA)    = lzma_with_size
+tool_$(CONFIG_KERNEL_LZO)     = lzo_with_size
+tool_$(CONFIG_KERNEL_XZ)      = xzkern_with_size
+tool_$(CONFIG_KERNEL_ZSTD)    = zstd22_with_size
+
+targets += vmlinux.bin.z
+$(obj)/vmlinux.bin.z: $(obj)/vmlinux.bin FORCE
+	$(call if_changed,$(tool_y))
+
+targets += $(notdir $(vmlinuzobjs-y))
+vmlinuzobjs-y := $(obj)/zkernel.o $(obj)/decompress.o $(obj)/string.o
+vmlinuzobjs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
+$(obj)/zkernel.o: $(obj)/vmlinux.bin.z
+AFLAGS_zkernel.o = $(KBUILD_AFLAGS) -DVMLINUZ_LOAD_ADDRESS=$(zload-y) -DKERNEL_ENTRY=$(entry-y)
+
+quiet_cmd_zld = LD      $@
+      cmd_zld = $(LD) $(KBUILD_LDFLAGS) -T $< $(vmlinuzobjs-y) -o $@
+
+targets += vmlinuz
+$(obj)/vmlinuz: $(src)/boot.lds $(vmlinuzobjs-y) FORCE
+	$(call if_changed,zld)
+	$(call if_changed,strip)
+
+targets += vmlinuz.efi
+$(obj)/vmlinuz.efi: $(obj)/vmlinuz FORCE
+	$(call if_changed,eficopy)
diff --git a/arch/loongarch/boot/boot.lds.S b/arch/loongarch/boot/boot.lds.S
new file mode 100644
index 000000000000..23e698782afd
--- /dev/null
+++ b/arch/loongarch/boot/boot.lds.S
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ld.script for compressed kernel support of LoongArch
+ *
+ * Author: Huacai Chen <chenhuacai@loongson.cn>
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include "../kernel/image-vars.h"
+
+/*
+ * Max avaliable Page Size is 64K, so we set SectionAlignment
+ * field of EFI application to 64K.
+ */
+PECOFF_FILE_ALIGN = 0x200;
+PECOFF_SEGMENT_ALIGN = 0x10000;
+
+OUTPUT_ARCH(loongarch)
+ENTRY(kernel_entry)
+PHDRS {
+	text PT_LOAD FLAGS(7); /* RWX */
+}
+SECTIONS
+{
+	. = VMLINUZ_LOAD_ADDRESS;
+
+	_text = .;
+	.head.text : {
+		*(.head.text)
+	}
+
+	.text : {
+		*(.text)
+		*(.init.text)
+		*(.rodata)
+	}: text
+
+	. = ALIGN(PECOFF_SEGMENT_ALIGN);
+	_data = .;
+	.data : {
+		*(.data)
+		*(.init.data)
+		/* Put the compressed image here */
+		__image_begin = .;
+		*(.image)
+		__image_end = .;
+		CONSTRUCTORS
+		. = ALIGN(PECOFF_FILE_ALIGN);
+	}
+	_edata = .;
+
+	.bss : {
+		*(.bss)
+		*(.init.bss)
+	}
+	. = ALIGN(PECOFF_SEGMENT_ALIGN);
+	_end = .;
+
+	/DISCARD/ : {
+		*(.options)
+		*(.comment)
+		*(.note)
+	}
+}
diff --git a/arch/loongarch/boot/decompress.c b/arch/loongarch/boot/decompress.c
new file mode 100644
index 000000000000..8f55fcd8f285
--- /dev/null
+++ b/arch/loongarch/boot/decompress.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author: Huacai Chen <chenhuacai@loongson.cn>
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/libfdt.h>
+
+#include <asm/addrspace.h>
+
+/*
+ * These two variables specify the free mem region
+ * that can be used for temporary malloc area
+ */
+unsigned long free_mem_ptr;
+unsigned long free_mem_end_ptr;
+
+/* The linker tells us where the image is. */
+extern unsigned char __image_begin, __image_end;
+
+#define puts(s) do {} while (0)
+#define puthex(val) do {} while (0)
+
+void error(char *x)
+{
+	puts("\n\n");
+	puts(x);
+	puts("\n\n -- System halted");
+
+	while (1)
+		;	/* Halt */
+}
+
+/* activate the code for pre-boot environment */
+#define STATIC static
+
+#include "../../../../lib/ashldi3.c"
+
+#ifdef CONFIG_KERNEL_GZIP
+#include "../../../../lib/decompress_inflate.c"
+#endif
+
+#ifdef CONFIG_KERNEL_BZIP2
+#include "../../../../lib/decompress_bunzip2.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZ4
+#include "../../../../lib/decompress_unlz4.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZMA
+#include "../../../../lib/decompress_unlzma.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZO
+#include "../../../../lib/decompress_unlzo.c"
+#endif
+
+#ifdef CONFIG_KERNEL_XZ
+#include "../../../../lib/decompress_unxz.c"
+#endif
+
+#ifdef CONFIG_KERNEL_ZSTD
+#include "../../../../lib/decompress_unzstd.c"
+#endif
+
+void decompress_kernel(unsigned long boot_heap_start)
+{
+	unsigned long zimage_start, zimage_size;
+
+	zimage_start = (unsigned long)(&__image_begin);
+	zimage_size = (unsigned long)(&__image_end) -
+	    (unsigned long)(&__image_begin);
+
+	puts("zimage at:     ");
+	puthex(zimage_start);
+	puts(" ");
+	puthex(zimage_size + zimage_start);
+	puts("\n");
+
+	/* This area are prepared for mallocing when decompressing */
+	free_mem_ptr = boot_heap_start;
+	free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
+
+	/* Display standard Linux/LoongArch boot prompt */
+	puts("Uncompressing Linux at load address ");
+	puthex(VMLINUX_LOAD_ADDRESS);
+	puts("\n");
+
+	/* Decompress the kernel with according algorithm */
+	__decompress((char *)zimage_start, zimage_size, 0, 0,
+		   (void *)VMLINUX_LOAD_ADDRESS, 0, 0, error);
+
+	puts("Now, booting the kernel...\n");
+}
diff --git a/arch/loongarch/boot/string.c b/arch/loongarch/boot/string.c
new file mode 100644
index 000000000000..3f746e7c2bb5
--- /dev/null
+++ b/arch/loongarch/boot/string.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/loongarch/boot/string.c
+ *
+ * Very small subset of simple string routines
+ */
+
+#include <linux/types.h>
+
+void __weak *memset(void *s, int c, size_t n)
+{
+	int i;
+	char *ss = s;
+
+	for (i = 0; i < n; i++)
+		ss[i] = c;
+	return s;
+}
+
+void __weak *memcpy(void *dest, const void *src, size_t n)
+{
+	int i;
+	const char *s = src;
+	char *d = dest;
+
+	for (i = 0; i < n; i++)
+		d[i] = s[i];
+	return dest;
+}
+
+void __weak *memmove(void *dest, const void *src, size_t n)
+{
+	int i;
+	const char *s = src;
+	char *d = dest;
+
+	if (d < s) {
+		for (i = 0; i < n; i++)
+			d[i] = s[i];
+	} else if (d > s) {
+		for (i = n - 1; i >= 0; i--)
+			d[i] = s[i];
+	}
+
+	return dest;
+}
+
+int __weak memcmp(const void *cs, const void *ct, size_t count)
+{
+	int res = 0;
+	const unsigned char *su1, *su2;
+
+	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) {
+		res = *su1 - *su2;
+		if (res != 0)
+			break;
+	}
+	return res;
+}
+
+int __weak strcmp(const char *str1, const char *str2)
+{
+	int delta = 0;
+	const unsigned char *s1 = (const unsigned char *)str1;
+	const unsigned char *s2 = (const unsigned char *)str2;
+
+	while (*s1 || *s2) {
+		delta = *s1 - *s2;
+		if (delta)
+			return delta;
+		s1++;
+		s2++;
+	}
+	return 0;
+}
+
+size_t __weak strlen(const char *s)
+{
+	const char *sc;
+
+	for (sc = s; *sc != '\0'; ++sc)
+		/* nothing */;
+	return sc - s;
+}
+
+size_t __weak strnlen(const char *s, size_t count)
+{
+	const char *sc;
+
+	for (sc = s; count-- && *sc != '\0'; ++sc)
+		/* nothing */;
+	return sc - s;
+}
+
+char * __weak strnstr(const char *s1, const char *s2, size_t len)
+{
+	size_t l2;
+
+	l2 = strlen(s2);
+	if (!l2)
+		return (char *)s1;
+	while (len >= l2) {
+		len--;
+		if (!memcmp(s1, s2, l2))
+			return (char *)s1;
+		s1++;
+	}
+	return NULL;
+}
+
+#undef strcat
+char * __weak strcat(char *dest, const char *src)
+{
+	char *tmp = dest;
+
+	while (*dest)
+		dest++;
+	while ((*dest++ = *src++) != '\0')
+		;
+	return tmp;
+}
+
+char * __weak strncat(char *dest, const char *src, size_t count)
+{
+	char *tmp = dest;
+
+	if (count) {
+		while (*dest)
+			dest++;
+		while ((*dest++ = *src++) != 0) {
+			if (--count == 0) {
+				*dest = '\0';
+				break;
+			}
+		}
+	}
+	return tmp;
+}
+
+char * __weak strpbrk(const char *cs, const char *ct)
+{
+	const char *sc1, *sc2;
+
+	for (sc1 = cs; *sc1 != '\0'; ++sc1) {
+		for (sc2 = ct; *sc2 != '\0'; ++sc2) {
+			if (*sc1 == *sc2)
+				return (char *)sc1;
+		}
+	}
+	return NULL;
+}
+
+char * __weak strsep(char **s, const char *ct)
+{
+	char *sbegin = *s;
+	char *end;
+
+	if (sbegin == NULL)
+		return NULL;
+
+	end = strpbrk(sbegin, ct);
+	if (end)
+		*end++ = '\0';
+	*s = end;
+	return sbegin;
+}
diff --git a/arch/loongarch/boot/zheader.S b/arch/loongarch/boot/zheader.S
new file mode 100644
index 000000000000..4bc50d953ec7
--- /dev/null
+++ b/arch/loongarch/boot/zheader.S
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <linux/pe.h>
+#include <linux/sizes.h>
+
+	.macro	__EFI_PE_HEADER
+	.long	PE_MAGIC
+coff_header:
+	.short	IMAGE_FILE_MACHINE_LOONGARCH		/* Machine */
+	.short	section_count				/* NumberOfSections */
+	.long	0 					/* TimeDateStamp */
+	.long	0					/* PointerToSymbolTable */
+	.long	0					/* NumberOfSymbols */
+	.short	section_table - optional_header		/* SizeOfOptionalHeader */
+	.short	IMAGE_FILE_DEBUG_STRIPPED | \
+		IMAGE_FILE_EXECUTABLE_IMAGE | \
+		IMAGE_FILE_LINE_NUMS_STRIPPED		/* Characteristics */
+
+optional_header:
+	.short	PE_OPT_MAGIC_PE32PLUS			/* PE32+ format */
+	.byte	0x02					/* MajorLinkerVersion */
+	.byte	0x14					/* MinorLinkerVersion */
+	.long	_data - efi_header_end			/* SizeOfCode */
+	.long	_end - _data				/* SizeOfInitializedData */
+	.long	0					/* SizeOfUninitializedData */
+	.long	__efistub_efi_pe_entry - _head		/* AddressOfEntryPoint */
+	.long	efi_header_end - _head			/* BaseOfCode */
+
+extra_header_fields:
+	.quad	0					/* ImageBase */
+	.long	PECOFF_SEGMENT_ALIGN			/* SectionAlignment */
+	.long	PECOFF_FILE_ALIGN			/* FileAlignment */
+	.short	0					/* MajorOperatingSystemVersion */
+	.short	0					/* MinorOperatingSystemVersion */
+	.short	0					/* MajorImageVersion */
+	.short	0					/* MinorImageVersion */
+	.short	0					/* MajorSubsystemVersion */
+	.short	0					/* MinorSubsystemVersion */
+	.long	0					/* Win32VersionValue */
+
+	.long	_end - _head				/* SizeOfImage */
+
+	/* Everything before the kernel image is considered part of the header */
+	.long	efi_header_end - _head			/* SizeOfHeaders */
+	.long	0					/* CheckSum */
+	.short	IMAGE_SUBSYSTEM_EFI_APPLICATION		/* Subsystem */
+	.short	0					/* DllCharacteristics */
+	.quad	0					/* SizeOfStackReserve */
+	.quad	0					/* SizeOfStackCommit */
+	.quad	0					/* SizeOfHeapReserve */
+	.quad	0					/* SizeOfHeapCommit */
+	.long	0					/* LoaderFlags */
+	.long	(section_table - .) / 8			/* NumberOfRvaAndSizes */
+
+	.quad	0					/* ExportTable */
+	.quad	0					/* ImportTable */
+	.quad	0					/* ResourceTable */
+	.quad	0					/* ExceptionTable */
+	.quad	0					/* CertificationTable */
+	.quad	0					/* BaseRelocationTable */
+
+	/* Section table */
+section_table:
+	.ascii	".text\0\0\0"
+	.long	_data - efi_header_end			/* VirtualSize */
+	.long	efi_header_end - _head			/* VirtualAddress */
+	.long	_data - efi_header_end			/* SizeOfRawData */
+	.long	efi_header_end - _head			/* PointerToRawData */
+
+	.long	0					/* PointerToRelocations */
+	.long	0					/* PointerToLineNumbers */
+	.short	0					/* NumberOfRelocations */
+	.short	0					/* NumberOfLineNumbers */
+	.long	IMAGE_SCN_CNT_CODE | \
+		IMAGE_SCN_MEM_READ | \
+		IMAGE_SCN_MEM_EXECUTE			/* Characteristics */
+
+	.ascii	".data\0\0\0"
+	.long	_end - _data				/* VirtualSize */
+	.long	_data - _head				/* VirtualAddress */
+	.long	_edata - _data				/* SizeOfRawData */
+	.long	_data - _head				/* PointerToRawData */
+
+	.long	0					/* PointerToRelocations */
+	.long	0					/* PointerToLineNumbers */
+	.short	0					/* NumberOfRelocations */
+	.short	0					/* NumberOfLineNumbers */
+	.long	IMAGE_SCN_CNT_INITIALIZED_DATA | \
+		IMAGE_SCN_MEM_READ | \
+		IMAGE_SCN_MEM_WRITE			/* Characteristics */
+
+	.org 0x20e
+	.word kernel_version - 512 -  _head
+
+	.set	section_count, (. - section_table) / 40
+efi_header_end:
+	.endm
diff --git a/arch/loongarch/boot/zkernel.S b/arch/loongarch/boot/zkernel.S
new file mode 100644
index 000000000000..13a8a14a2328
--- /dev/null
+++ b/arch/loongarch/boot/zkernel.S
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <asm/addrspace.h>
+#include <asm/asm.h>
+#include <asm/loongarch.h>
+#include <asm/regdef.h>
+#include <generated/compile.h>
+#include <generated/utsrelease.h>
+
+#ifdef CONFIG_EFI_STUB
+
+#include "zheader.S"
+
+	__HEAD
+
+_head:
+	/* "MZ", MS-DOS header */
+	.word	MZ_MAGIC
+	.org	0x28
+	.ascii	"Loongson\0"
+	.org	0x3c
+	/* Offset to the PE header */
+	.long	pe_header - _head
+
+pe_header:
+	__EFI_PE_HEADER
+
+kernel_asize:
+	.long _end - _text
+
+kernel_fsize:
+	.long _edata - _text
+
+kernel_vaddr:
+	.quad VMLINUZ_LOAD_ADDRESS
+
+kernel_offset:
+	.long kernel_offset - _text
+
+kernel_version:
+	.ascii  UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") " UTS_VERSION "\0"
+
+SYM_L_GLOBAL(kernel_asize)
+SYM_L_GLOBAL(kernel_fsize)
+SYM_L_GLOBAL(kernel_vaddr)
+SYM_L_GLOBAL(kernel_offset)
+
+#endif
+
+	__INIT
+
+SYM_CODE_START(kernel_entry)
+	/* Save boot rom start args */
+	move	s0, a0
+	move	s1, a1
+	move	s2, a2
+	move	s3, a3
+
+	/* Config Direct Mapping */
+	li.d	t0, CSR_DMW0_INIT
+	csrwr	t0, LOONGARCH_CSR_DMWIN0
+	li.d	t0, CSR_DMW1_INIT
+	csrwr	t0, LOONGARCH_CSR_DMWIN1
+
+	/* Clear BSS */
+	la.abs	a0, _edata
+	la.abs	a2, _end
+1:	st.d	zero, a0, 0
+	addi.d	a0, a0, 8
+	bne	a2, a0, 1b
+
+	la.abs	a0, .heap	   /* heap address */
+	la.abs	sp, .stack + 8192  /* stack address */
+
+	la	ra, 2f
+	la	t4, decompress_kernel
+	jirl	zero, t4, 0
+2:
+	move	a0, s0
+	move	a1, s1
+	move	a2, s2
+	move	a3, s3
+	PTR_LI	t4, KERNEL_ENTRY
+	jirl	zero, t4, 0
+3:
+	b	3b
+SYM_CODE_END(kernel_entry)
+
+	.comm .heap, BOOT_HEAP_SIZE, 4
+	.comm .stack, BOOT_STACK_SIZE, 4
+
+	.align 4
+	.section .image, "a", %progbits
+	.incbin "arch/loongarch/boot/vmlinux.bin.z"
diff --git a/arch/loongarch/tools/Makefile b/arch/loongarch/tools/Makefile
new file mode 100644
index 000000000000..8a6181c82a91
--- /dev/null
+++ b/arch/loongarch/tools/Makefile
@@ -0,0 +1,15 @@
+#
+# arch/loongarch/boot/Makefile
+#
+# Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+#
+
+hostprogs := elf-entry
+PHONY += elf-entry
+elf-entry: $(obj)/elf-entry
+	@:
+
+hostprogs += calc_vmlinuz_load_addr
+PHONY += calc_vmlinuz_load_addr
+calc_vmlinuz_load_addr: $(obj)/calc_vmlinuz_load_addr
+	@:
diff --git a/arch/loongarch/tools/calc_vmlinuz_load_addr.c b/arch/loongarch/tools/calc_vmlinuz_load_addr.c
new file mode 100644
index 000000000000..5e2ca6b4dff6
--- /dev/null
+++ b/arch/loongarch/tools/calc_vmlinuz_load_addr.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+int main(int argc, char *argv[])
+{
+	unsigned long long vmlinux_size, vmlinux_load_addr, vmlinuz_load_addr;
+	struct stat sb;
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: %s <pathname> <vmlinux_load_addr>\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	if (stat(argv[1], &sb) == -1) {
+		perror("stat");
+		return EXIT_FAILURE;
+	}
+
+	/* Convert hex characters to dec number */
+	errno = 0;
+	if (sscanf(argv[2], "%llx", &vmlinux_load_addr) != 1) {
+		if (errno != 0)
+			perror("sscanf");
+		else
+			fprintf(stderr, "No matching characters\n");
+
+		return EXIT_FAILURE;
+	}
+
+	vmlinux_size = (uint64_t)sb.st_size;
+	vmlinuz_load_addr = vmlinux_load_addr + vmlinux_size;
+
+	/*
+	 * Align with 64KB: KEXEC needs load sections to be aligned to PAGE_SIZE,
+	 * which may be as large as 64KB depending on the kernel configuration.
+	 */
+
+	vmlinuz_load_addr += (0x10000 - vmlinux_size % 0x10000);
+
+	printf("0x%llx\n", vmlinuz_load_addr);
+
+	return EXIT_SUCCESS;
+}
diff --git a/arch/loongarch/tools/elf-entry.c b/arch/loongarch/tools/elf-entry.c
new file mode 100644
index 000000000000..c80721e0dee1
--- /dev/null
+++ b/arch/loongarch/tools/elf-entry.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <elf.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+__attribute__((noreturn))
+static void die(const char *msg)
+{
+	fputs(msg, stderr);
+	exit(EXIT_FAILURE);
+}
+
+int main(int argc, const char *argv[])
+{
+	uint64_t entry;
+	size_t nread;
+	FILE *file;
+	union {
+		Elf32_Ehdr ehdr32;
+		Elf64_Ehdr ehdr64;
+	} hdr;
+
+	if (argc != 2)
+		die("Usage: elf-entry <elf-file>\n");
+
+	file = fopen(argv[1], "r");
+	if (!file) {
+		perror("Unable to open input file");
+		return EXIT_FAILURE;
+	}
+
+	nread = fread(&hdr, 1, sizeof(hdr), file);
+	if (nread != sizeof(hdr)) {
+		fclose(file);
+		perror("Unable to read input file");
+		return EXIT_FAILURE;
+	}
+
+	if (memcmp(hdr.ehdr32.e_ident, ELFMAG, SELFMAG)) {
+		fclose(file);
+		die("Input is not an ELF\n");
+	}
+
+	switch (hdr.ehdr32.e_ident[EI_CLASS]) {
+	case ELFCLASS32:
+		/* Sign extend to form a canonical address */
+		entry = (int64_t)(int32_t)hdr.ehdr32.e_entry;
+		break;
+
+	case ELFCLASS64:
+		entry = hdr.ehdr64.e_entry;
+		break;
+
+	default:
+		fclose(file);
+		die("Invalid ELF class\n");
+	}
+
+	fclose(file);
+	printf("0x%016" PRIx64 "\n", entry);
+
+	return EXIT_SUCCESS;
+}
-- 
2.27.0